The European Union planned new sanctions against Syria, spokesman Michael Mann said Wednesday, as opposition activists said government troops killed 21 more people in a months-long crackdown.

European nations have been pushing for tough measures against Syria, where more than 5,000 people have been killed since demonstrations began in March 2011, according to the United Nations.

The EU announcement comes as the Local Coordination Committees of Syria, an opposition umbrella group, said 21 more people were killed by government troops on Wednesday. Of those, 13 were killed in Homs, the scene of the worst violence in recent weeks, with the rest scattered around the country, the LCC said.

The EU will place restrictions on 22 more individuals and eight more companies starting on Monday, said a source familiar with the decision who asked not to be named, talking about an announcement that had not yet been made.

Elsewhere, four people were killed in Idlib, two in the Damascus suburbs, one in Aleppo and one in Daraa.

The state-run Syrian Arab News Agency, meanwhile, said 15 police officers and soldiers, including an army colonel, had been killed in recent fighting. CNN cannot independently verify events in Syria because its government restricts the activity of journalists there.

An Arab League monitoring mission has been in Syria since late December, but its mandate expires Wednesday as the league and the Syrian government negotiate over an extension, said Ambassador Adnan Al Khudeir, the Cairo-based head of the monitoring operation.

All 15 monitoring teams have been told to remain at their bases on Thursday, a source close to the monitoring mission in Damascus told CNN.

The monitors have been greeted ecstatically in some Syrian cities, where residents have recounted tales of government brutality. In the town of Kisweh, which monitors visited on Tuesday, one demonstrator spray-painted the letters "S.O.S." on a wall; on Sunday, crowds in Zabadani carried the monitors on their shoulders and urged them to stay to prevent reprisals.

While Western powers have imposed sanctions on Syria during the 10-month crackdown, opposition by Russia and China has kept the U.N. Security Council from following suit. Russian Foreign Minister Sergey Lavrov said Wednesday that Moscow did not consider sanctions that were unilaterally imposed on Syria by the West as legitimate.

"Unilateral sanctions are always a derogation of the collective efforts of Syria. ... If someone wants to use the U.N. Security Council, it is necessary to discuss everything there, whether we need sanctions or not ... (and) which methods apart from sanctions to use," Lavrov said.

He said unspecified "Western countries" were trying to remove U.N. restrictions on the use of force against Syria in hopes of launching a military operation similar to the NATO-led campaign in Libya last year.

"The approach of our Western colleagues is one-sided," Lavrov told journalists in Moscow. "An attack on Syria will not be approved by the U.N., which leaves the attackers fully responsible for their deeds."

Within Syria, dozens of members of the country's leading religious minority put out a statement denouncing what they said were efforts by both sides to turn the uprising into a religious conflict.

The statement was signed by more than 100 members of the Alawite sect, an offshoot of Shiite Islam that includes Syria's ruling al-Assad family. The signers said they want to see the ouster of "the current regime and dictatorship," but criticized "careless statements" by opposition leaders they said gave the uprising a "sectarian facet."

"We invite the Syrian Alawites and those who belong to all religious and political minorities in Syria, who are afraid from what's succeeding the regime's ouster, to participate in toppling this bloody regime and cooperate with us to build the new Syrian Republic; a country of law and nationalism," they wrote. "We condemn any actual or verbal forms coming from the oppositions' members and considered as an offense of the entire Syrian people and the future of this country. We also hope that all of the opposition parties condemn such reckless acts and statements."